Here is what the owner said about the CV joints and what his FE was:
The clicking noise is worse when turning and is barely noticeable when going straight. It has not really gotten any worse over the time that it has been bad...but I really do not drive it much. The muffler is not trerribly loud. It is defintely much louder when accelerating. Not so bad when idling.
Gas mileage lately is in the upper 30's. When I was doing a lot of highway driving it got up into the 40's. It still seems to do pretty well but the few times I drive it it is all city driving. It has been a great car as far as mileage goes.
So is high 30's in the city and 40's on the Highway even possible for a VX? Do the CV joints sound like they will make the 500 mile drive?